DESCRIPTION (provided by applicant: This proposal requests four years of support (12/01/2014-11/30/2018) to conduct secondary analyses of data from two national studies to gain an understanding of the natural history and risk factors for non-medical prescription drug use (NMPDU) (stimulants, sedatives, tranquilizers, pain relievers) in different groups in the US population. Four aims will be pursued. (1) To determine the position of NMPDU in the developmental sequence of drug involvement and, in particular, the role of Gateway drugs, nicotine, alcohol and marijuana, in the progression to NMPDU and compare adolescents and adults (NSDUH). (2) (a) To specify the association between parent and child on NMPDU, (b) to compare the association between parent and child on NMPDU with the association on three other drug classes: cigarettes, alcohol, marijuana, (c) to identify the role of neighborhood factors on the association between parent and child on NMPDU (NSDUH). (3) To specify the extent of genetic liability for NMPDU in the context of different neighborhoods (Add Health). (4) To compare males vs. females and three racial/ethnic groups in Aims (1) - (3). Analyses will be conducted in two national data sets: (1) multiple surveys of the National Survey on Drug Use and Health, the annual nationally representative survey of drug use in the general US population aged 12 and older. The total samples as well as subsamples of matched parent-child pairs will be analyzed. (2) National samples of twins, full sibling, half-sibling pairs, and cousin in the National Longitudinal Study of Adolescent Health, a four-wave longitudinal study of former 7th-12th graders. The effects of neighborhood characteristics, including census-based indicators of neighborhood disadvantage and substate region rates of NMPDU, will also be considered. The analysis of the position of NMPDU in the developmental sequence of drug involvement, the analysis of a national sample of parent-child dyads, the assessment of genetic liability and the impact of neighborhood characteristics on NMPDU represent particularly unique and novel aspects of the proposed research. This program of epidemiological research addresses a crucial public health problem in the nation and, by providing a multifaceted understanding of NMPDU, will inform the development and implementation of prevention and intervention efforts designed to reduce NMPDU, and suggest hypotheses to be tested in animal models.